The six deceased had been acquainted with or had financial troubles with the woman, who was an employee of a bar in the city of Tottori, and police are investigating their deaths with a view to building murder cases.
In the latest development, the two are suspected of conspiring to defraud a local appliance shop of about 1.23 million yen worth of goods between Oct. 8 and Oct. 15.
In their indictments, the man is charged with swindling a tractor from a dealer and the woman with cheating an acquaintance of 1.26 million yen. They were arrested Nov. 2.